MAP / Turbo Boost sensor

[Tlysne]

Hey Guys, 

 

I dug around and tried to see if anyone has posted this so apologies if someone has. Trucks a 2001. Does anyone know if I can test the MAP / Turbo Boost sensor for voltage or to see if its bad? I have a FASS Titanium and 5" exhaust turbo back and that's it. I had a quadzilla at one point which I removed when I got the truck. Had the APPS filter tap and the ECU, removed that. 

 

For about a month I have been struggling with my truck having zero power after half throttle. No power, no acceleration, no B*lls. Here is a list of things that I have tested or changed. 

 

APPS - Made sure to unhook batteries and have the ECU relearn the position after I set the voltage with a meter. 

VSS - Vehicle speed sensor - Threw a code and its gone now

Output shaft sensor - replaced- code gone

Overflow valve

Fuel filters on the fass  - Pressure on fass system is 20 psi on the gauge - 13 volts continuous while driving

Fuel lines replaced - return,supply, and to VP - was getting small amounts of air from supply line. 

 

Tested:

Batteries - 12.68 volts resting unhooked completely. Clean terminals and no extras on terminals

Alt noise - .025 vAC

 

Ran OBD II - Bad sending unit which I have had for 2 years - go off mileage 

                      Grid heater code but its 95 degrees and it popped up after all this has been going on.

 

Ran OBD in Gauge mode and finally noticed that the truck key on not running, or running idle says 13.3-13.5 psi boost. It maxes out at 15.1 psi. When it is hotter out and humid it runs real bad and when it cools off at night it runs better and with some help I think it may be a MAP sensor issue. Is there a way to test it? I unplugged it and drove the truck and it acts the exact same, just worse.

 

I know this is alot but I figure the more I tell the less back and forth there will be. This is my daily driver and I cant afford to not have it. Any help would be great. 

 

Cheers

 

 

[Me78569]

4.5 v = 0 psi .5 v = ~50 psi.  you should see voltage drop from 4.5v to .5v as boost increases

[Tlysne]

@Me78569 Do you know which of the three wires I should test? 

[Me78569]

The articles section has wiring diagrams